Cerebral Palsy (CP) is a non-progressive disorder of the central nervous system acquired early in life that results in abnormalities of movement. Physical therapy (PT) is a commonly used treatment aimed at ameliorating dysfunction. Despite the costly nature of long-term PT, little scientific evidence of its cost effectiveness exists. Survey research has suggested that physicians believe that PT produces a modest positive impact on children with CP, but substantial positive effects on the family. Individual physicians differ greatly, however, in how much they use physical therapy and the basis for this variation is unknown. Our research explores the nature of physicians' beliefs in the efficacy of PT in management of children with CP and will identify differences in referral decisions based on physician and child characteristics. Of particular interest is whether medical specialists of various types make different decisions regarding referral. The methodology used is a questionnaire with case descriptions and videotapes of 10 children with motor dysfunction. The cases represent specific types of CP and a range of severity. Physicians (N=125) who are either specialists in CP or general pediatricians who have previously provided extensive information on their beliefs regarding the efficacy of PT, their training and experience, and their current referral practices, will be surveyed. As they view the tapes, they will respond to questions regarding whether they would refer each child to PT and what outcomes they expect. The factors influencing physicians' decisions to refer are expected to be: training, medical specialty, and experience with CP; the child's symptoms and degree of severity; and the physicians' beliefs regarding the efficacy of PT in ameliorating CP motor dysfunction. The broad domain underlying this research is that of analysis of clinical decision making under conditions of uncertainty. Mathematical modeling of clinical decisions can reveal inconsistencies in judgments, bias in weighing relevant variables, and other evidence of less than ideal analysis of signs and symptoms with outcome probabilities. The significance of this work is that: 1) decisions will be compared across medical specialties; 2) decisions can be compared with previously reported training in developmental disabilities, beliefs in PT efficacy and propensities to refer; and 3) decisions will be captured in a period of increased uncertainty regarding both CP diagnosis and PT efficacy.